Cook peeled potatoes in a large saucepan of boiling, salted water for 10 to 12 minutes or until just tender. Drain. Set aside to cool. Halve potatoes.
Meanwhile, heat oil in a large frying pan over medium-high heat. Cook chicken for 5 to 6 minutes each side, or until browned and cooked through. Transfer to a plate. Cover. Stand for 5 minutes. Slice chicken.
Arrange lettuce, potato, chicken and egg on serving plates. Drizzle with dressing. Season with salt Sprinkle with spring onions. Serve.